Surface Defect Generation on SnO₂Nanoparticles Using High-Energy Ball Milling for H₂S Gas Sensor Applications

Hydrogen sulfide (H₂S) is a highly toxic and dangerous gas with a flammable and corrosive nature, making the development of reliable gas sensors for its detection vital. This study investigated the enhancement in H₂S gas sensing performance of commercial SnO₂powders after high-energy milling. SnO₂powders were subjected to high-energy milling for 30, 60, and 90 min and then were characterized using advanced techniques to evaluate their morphology, chemical composition, and crystallinity. The response of a pristine SnO₂gas sensor, and ones where the SnO₂was milled for 30, 60 and 90 min, were 2.46, 2.27, 3.01, and 1.98, respectively, to 10 ppm H₂S at 300°C. Thus, the H₂S gas sensing results revealed that the SnO₂powders milled for 60 min exhibited the highest sensing performance. This improvement in H₂S sensing performance was attributable to the reduced particle sizes achieved through the high-energy milling process, which increased the surface area and created defects on the surface of the SnO₂particles, thereby enhancing the interaction between the gas molecules and sensor material. The smaller morphological size of the particles and surface defects subsequently promoted the resistance modulation crucial for H₂S gas detection. This study demonstrates that high-energy ball milling can effectively boost the gas-sensing features of SnO₂powders. The findings can provide guidance for enhancing the gas-sensing capabilities of other resistive sensors.